To enable a user to interact with modern electronic devices, such devices typically comprise one or more user-manipulatable elements that provide mechanisms for converting user input into signals, typically electrical signals, that can be received and processed by the modern electronic device. Such user-manipulatable elements can include keyboards, mice, trackballs, joysticks, and other like devices that can be communicationally coupled to the electronic device through either wired or wireless communicational mechanisms.
Popular among modern electronic devices that are designed to be lightweight and portable are touch-based user-input receivers, such as a touch screen that can, within the same, or approximately the same area, both display visual information to the user and receive the touch-based input from the user. Traditionally, touch screens are designed such that a user's touch to an area of the touch screen is received and interpreted within the context of the visual information, or graphical element, being displayed in, or proximate to, that area.
Touch screens can be implemented utilizing any of several types of electromechanical mechanisms, including resistive, capacitive, infrared, surface acoustic wave and other like electromechanical mechanisms. For example, touch screens implemented utilizing resistive mechanisms typically comprise multiple transparent layers with electrically conductive coatings that are physically separated such that, when the touch screen is depressed by a user, the multiple conductive layers make contact with one another, causing electrical current to flow between them and, thereby, enabling a sensing mechanism to detect the user's touch. As another example, touch screens implemented utilizing surface acoustic wave mechanisms typically comprise at least one layer through which acoustic waves, generated by transducers attached to the layer, are propagated. When a user touches the layer, the acoustic energy is absorbed and sensors attached to the layer detect such a change and, thereby, detect the user's touch.
Many modern touch screens are implemented with capacitive mechanisms, including self capacitance sensing arrangements and mutual capacitance sensing arrangements. A touch screen implemented with a self capacitance sensing arrangement can comprise at least one layer of charged electrodes and traces such that, when a user touches, or places their finger in close proximity, to the touch screen, the charge from at least one of the charged electrodes is at least partially transferred to the user's finger, thereby affecting the capacitance of the charged electrode and, consequently, enabling a sensing mechanism to detect the user's touch. A touch screen implemented with a mutual capacitance sensing arrangement can comprise multiple layers of spatially separated and intersecting conductive traces, such that, at each intersection, a capacitive coupling node is formed. As with the self capacitance sensing arrangement, when a user touches, or places their finger in close proximity to, the touch screen, charge from at least one capacitive coupling node is transferred, at least partially, to the user's finger, again enabling sensing mechanisms to detect the user's touch due to the resulting change in capacitance.